Making artificial threads



" products were not very fast.

Patented Nov. 30, 1937 UNITED STATES PATENT OFFICE MAKING ARTIFICIAL THREADS Leon Lilienfeld, Vienna, Austria 12 Claims.

The artificial filaments and threads, particularly artificial silks, made from alkyl celluloses according to the previous processes possess the great disadvantages of not being capable of being readily dyed by means of substantive or acid dyes, it is only with difficulty, that they can be dyed (to some extent) with basic dyes. Treated with substantive or acid dyes, the previously known alkyl cellulose silks gave practically no dyeing. They did not absorb and permanently retain the dye, to the desired extent (and in most cases they did not absorb the dye to any useful extent). Even on treatment with basic dyes only weak shades were obtained, and the dyed Only by incorporation of the dye with the spinning solution itself could deeper colors be obtained with the heretofore known alkyl cellulose silks.

This difiiculty is overcome by the present invention. I have made the discovery that if very definite alkyl celluloses .ormixtures of or containing alkyl celluloses be used for the production of artificial silk, that is such alkyl celluloses (or mixture of or containing alkyl celluloses), as are insoluble in water at and above 16 C., but which swell or are even soluble in water at some temperature below 16 C., particularly in water at below C., artificial silks are formed which may be colored to any desired shade directly, either with substantive (direct dyeing) dyes or with acid dyes. The new artificial silks also permit dyeing with vat dyes, or with sulfur dyes, or with mordant dyes.

The new artificial silks may consist solely of the alkyl celluloses themselves which are insoluble in water at and above 16 C., but which swell or are soluble in water below 10 C'., or of mixtures of such alkyl celluloses with other cellulose derivatives (as for example nitrocelluloses, acetyl celluloses, formyl celluloses or the like), or other colloidal bodies, with or without plasticizing or softening agents (as for example oils, camphor, or camp-her substitutes, high boiling esters including phosphoric acid esters of phenols, and

' the like).

16 C., and above, but which swell or are soluble in water below this temperature, particularly below 10 C., may for example be accomplished by treating an ethyl derivative of a cellulosic body soluble in water at 16 C'., with a caustic alkali and an ethylating agent, while the content by weight of the reaction mixture in caustic alkali is not less than one-tenth and not more than one-fourth of the quantity of. the water contained in the reaction mass. Such alkyl celluloses may also be manufactured by treating an alkali-insoluble cellulosic material with alkylating agents in the presence of between about 0.3 and about 2.5 parts by weight of water to 1 part by weight of the cellulosic material, and in the presence of between about 0.6 and about 3 parts by weight of caustic alkali to 1 part by weight of the cellulosic material. is, however, not limited to the use of alkyl ethers of cellulose prepared according to these two processes. Regardless of the method or process by which they are made, any alkyl ethers of cellulosic bodies which ethers are insoluble in water at 16 C., and above, but which swell or even dissolve partly or wholly in water below this temperature, particularly below 10 C., may be employed for the execution of the present invention. This subject matter is claimed in my concurrent applications Serial Numbers 567,426 and. 567,340, filed June 10, .1922. This latter case is now Patent No. 1,505,043.

For making artificial silk such as alkyl cellulose insoluble in water at 16 C., or above, but swelling or even soluble in water at lower temperatures, especially below 10 C., (for example, such as ethyl cellulose or methyl cellulose), is dissolved in suitable solvents or solvent mixtures, (for example, benzol, ethyl alcohol, methyl alcohol, a mixture ofbenzol and ethyl alcohol, a mixture of benzol and methyl alcohol, a mixture of trichlorethylene or acetylene dichloride (dichlorethylene) and ethyl alcohol, a mixture of trichlorethylene or acetylene dichloride (dichlorethylene) and methyl alcohol, a mixture of benzol dichlorethylene (acetylene dichloride and methyl alcohol, a mixture of chloroform and ethyl alcohol, a mixture of chloroform and methyl alcohol, a mixture of tetrachlorethane and ethyl alcohol or methyl alcohol, a mixture of acetone and alcohol, a mixture of acetone, benzol and alcohol, a mixture of acetone, chloroform and alcohol, a mixture of methyl acetate, benzol and ethyl or methyl alcohol, chloroform, glacial acetic acid, formic acid, a mixture of methyl or ethyl acetate and ethyl alcohol, a mixture of methyl acetate The present invention or ethyl acetate and methyl alcohol, methyl acetate, ethyl acetate, other esters of organic acids in themselves or in mixture with ethyl alcohol or methyl alcohol etc. etc.) and then spun through fine nozzles or openings, into filaments, threads and the like. The solutions may also have added other cellulose derivatives (as for example acetyl celluloses, formyl celluloses or nitro celluloses, or the like) or other colloids (as for example resins, balsams, condensation products of phenols and aldehydes, india rubber, balata, gutta-percha etc. etc.) or softening agentsor agents to make the products pliable or plastic (as for example drying or non-drying oils, fats, fatty acids, phosphoric acid esters of the phenols, high boiling aromatic hydrocarbons, camphor, naphthalene, or its derivatives, metal compounds of fatty acids, ethers of phenols, formanilid, acetanilid, sugars, glycerine etc. etc.). If such alkyl ethers of cellulosic bodies be employed as are insoluble in water at 16 C., and above, but soluble in very cold water (for example in water at 6 C. and below) very cold water may be taken as solvent. In such cases the solutions may also have added other colloids soluble in aqueous liquids (as for example cellulose xanthogenates (viscose), cuprammonium-cellulose, artificial silk waste in alkaline solution, cellulose hydrates or hydrocelluloses or oxycelluloses soluble in aqueous solutions of alkalies, casein, albumen, proteids, fibroin (real silk or real silk waste) keratine, (all of which are soluble in aqueous solutions of alkalies), starch, dextrine, tragasol, gum tragacanth etc. etc.), or water-soluble softening agents (as for example glycerine, sugars, soaps, Turkey red oil etc.)

Among the above examples of mixed liquids, the mixture of tetrachlorethane and ethyl or methyl alcohol is particularly referred to. In this mixture, the tetrachlorethane has a boiling point of about or 147 C., and ethyl alcohol boils at about78 C., and methyl alcohol boils at about 66 C. Methyl and ethyl alcohols are both excellent solvents for the particular kinds of cellulose ethers herein described, while tetrachlorethane alone would be a non-solvent therefor. In other words these particular cellulose ethers dissolve in a mixture of methyl or ethyl alcohol and tetrachlorethane, and also would dissolve in methyl alcohol or in ethyl alcohol alone, but would not dissolve in tetrachlorethane alone. The tetrachlorethane is far less volatile than either of the two alcohols. It is also well known that both methyl alcohol and ethyl alcohol are readily soluble in water and that tetrachlorethane is not.

The fibres leaving the fine nozzles or capillary openings may either be immediately dried, or (as claimed herein) conducted through suitable precipitating baths in which the employed cellulose ethers are insoluble. As a rule, to which however the present invention is not limited, it may be regarded that, if solutions of alkyl ethers of cellulose in solvents other than water are employed, water is the preferable and most economical precipitating bath. The temperature of the water, employed as a precipitating bath, has to be adapted to the properties of the cellulose ether employed. In other words, the water employed as a precipitating bath must have a temperature at which the cellulose alkyl ether in question is insoluble and in which it does not swell up to a detrimental extent. In general, water at 16 C., or above will answer the purpose. The water, used as the precipitating bath, may

have added other substances either accelerating the act of precipitation or improving the artificial filaments particularly silk with regard to its properties such as lustre, suppleness, strength and the like, as for example salts, inorganic or organic acids, acid salts, alkalies, sugars or other water-soluble carbohydrates, glycerine etc. etc. Water, as a precipitating bath, turns out well also in cases in which the solutions of the alkyl ethers of cellulosic bodies have added other cellulose derivatives or other colloids soluble in the same solvents, but insoluble in water. As precipitating baths for solutions of the alkyl ethers of cellulose may, besides water, be employed any substance in which the alkyl ether of cellulose employed is insoluble, for example petrol, ligroin, petroleum, or other aliphatic hydrocarbons etc.

If cellulose alkyl ethers be used that not only swell up, but also dissolve in very cold water, then water at temperatures at which the cellulose ether in question is insoluble may also be used as the precipitating bath. Here too water atv 16 C. or above will meet all requirements and to it may be added salts, acids, alkalies, sugars, glycerine etc. Such additions will be particularly necessary if the solutions of the cellulose ethers contain other colloids soluble in aqueous solutions and requiring for their precipitation salts, acids, or salts and acids, or alkalies or the like (for example cellulose xanthogenates, cuprammonium-cellulose, albumens, fibroin, casein, silk, silk waste, cellulose hydrates and the like).

The artificial fibres or threads made in this way, may be treated with tanning materials either after finishing or at any stage of their manufacture for the purpose of eliminating or decreasing their swelling property or solubility in very cold water. This may be done by treating the artificial threads or fibres manufactured according to the present process after a previous swelling in very cold'water with solutions of reagents capable of precipitating albumen, particularly natural tanning materials or their substitutes for example with an aqueous solution of tannic acid. They do not lose their transparency and luster thereby, and may be washed, if desired, and dried without suffering appreciably in appearance. They have attained, however, the valuable property of being insoluble or not swelling or swelling only very slightly (less than the original article) in cold water. This subject matter is claimed in my concurrent application 567,429, (now Patent No. 1,505,044).

The artificial threads or fibres made according to the present process may be used as a substitute for natural threads or fibres, such as silk or the like; they are however, if suit-ably made, also suited for use as a substitute for animal hair (e. g. horsehair). The artificial silks made according to the present process have a beatiful luster and good pliability. They are difierentiated from the artificial silks previously made from alkyl celluloses in that they may be dyed either with substantive (direct dyeing) dyes, or with acid dyestuffs, to give any desired shades, and that they may also be given any desired depth or nuances of color with basic dyes. They also can be dyed with vat dyes or with sulfur dyes and the like.

The dyeing of the new spinning fibres is accomplished, for example, according to the process of the U. S. patent application filed on June 10, 1922, No. 567,427, (now Patent No. 1,890,392) for colored articles of alkyl celluloses and dyeing process therefor, which process consists essen- T may be washed with water.

tially in causing the artificial silk or artificial fibres made according to the present process, to swell in very cold water, and then treating the same with the desired dyestuff in the manner in which that particular dyestuff is ordinarily used.

Without restricting myself to details, the following examples are given, by way of illustration:

Example I 40 to 80 parts by weight of an ethyl ether of cellulose insoluble in water at 16 0., but soluble in water at about 5 to 8 C., and below (prepared for example, by treating 100 parts by weight of cellulose with 200 parts by weight of a 50% solution of caustic soda and 100 parts by weight of pulverized caustic soda (whereby the mass attracts 20 to 60 parts by weight of Water from the air) and exposing this mixture to the action of 310 parts by weight of ethyl chloride at a temperature of 90 to 150 C., for 8 to 12 hours, or by treating 2400 parts by weight of an aqueous alkaline solution of a purified cellulose xanthate containing about 200 parts by weight of the original cellulose and about 200 parts by weight of caustic soda with 500 to 600 parts by weight of di-ethyl sulphate at a temperature of about 50 to 55 0., adding to the reacting mixture 324 parts by weight of solid caustic soda in five portions and 1470 parts by weight of di-ethyl sulphate also in five portions, heating after each of these additions to 60 to 90 C., and isolating the finished cellulose ether by washing with water or water, acid and water and drying) are, preferably with stirring or kneading, dissolved in 4:00 to 500 parts by weight of a suitable solvent or solvent mixture (for example in a mixture of '75 to 100 parts by weight of methyl alcohol and 385 to 400 parts by weight of dichlorethylene (acetylene dichloride), or in a mixture of 80 to 100 parts by weight of benzol, 250 to 300 parts by weight of dichlorethylene and '75 to 100 parts by weight of methyl alcohol, or in a mixture of 75 to 100 parts by weight of methyl or ethyl alcohol and 350 to 400 parts by weight of chloroform, or in a mixture of 80 to 250 parts by weight of methyl acetate and 200 to 400 parts by weight of methyl alcohol, or in 400 to 600 parts by weight of a mixture of benzol and ethyl or methyl alcohol 1:3). The thus obtained viscous solution is, if necessary, filtered, and if necessary allowed to stand at room temperature, or at S5- l C. in order to remove any air bubbles contained therein.

The solution is then, in known manner, spun through fine nozzles or openings and the threads leaving the nozzles or capillary openings are either dried directly, or conducted through a precipitating bath in which the cellulose ether is insoluble, for example through water at room temperature, or above, which causes the threads to congeal. To the water may be added other substances either accelerating the precipitation or the congealing, or improving the lustre or uppleness or other properties of the threads, such as salts, acid salts, glycerine, sugars, lactic acid, glycols, etc. etc. The time during which the threads are in contact with the precipitating bath should SUffiCe to bring about such a degree of toughness as to allow of the threads being wound. This time may be regulated either by the speed at which the threads go through the precipitating bath, or by the length of the vessel containing the precipitating bath, or by both. If necessary, the threads leaving the precipitating bath It is preferable to keep the threads during the procedure of spinning and. precipitating in a stretched state, which may be attained, for example, by giving an appropriate speed to the roller or other appliance on which the threads are wound on leaving the precipitating bath. The threads may be dried in the WOlllld. state or before they are wound, or they may be partly dried on their way from. the precipitating bath to the appliance for winding and then completely dried on said appliance. The drying may be effected at room temperature or warm or hot.

The obtained artificial silk shows a fine lustre, is very strong, pliable, soft, resistant to water at 16 C. and to alkalies, and can be dyed with substantive (direct) dyes or with acid dyes, or with vat dyes, or with sulphur dyes, or with mordant dyes, or with basic dyes, etc.

In order to render it resistant, or more resistant to water at below 10 C. or so and insoluble in water at about C. and below, it may be treated with tanning materials. This may be accomplished for example by incorporating with the precipitating bath 1 to of a tanning material, for example tannic acid, or by treating the wet threads on the winding appliance or on the way to the winding appliance, with a solution of a tanning material, for example tannic acid, or by swelling the finished threads in water at a temperature at which they are water-insoluble, in this case at say about 8 C. and treating them afterwards with a solution of a tanning agent, or by treating them in the dyed state in the last mentioned manner, or the like.

The dyeing of the threads may be accomplished by exposing the article to the action of water at a temperature at which it will swell, and treating the same with a dye solution.

Example II The method of operation is the same as in Example I, but with the difierence that for making the solution designed for spinning an ethyl ether of cellulose is employed that is insoluble in water at 16 C., but slightly swells in water at 9 to 10 C., and distinctly swells in water at between 5 and 8 0., such ether being insoluble in Water at 1 C., but becoming friable in water at 1 to 5 C. These swelling phenomena may be seen best if the cellulose ether is converted into a film or thread. Such ethyl ethers may be prepared by mixing 100 parts by weight of finely divided sulfite cellulose with 100 parts by Weight of a 50% solution of caustic soda and 100 to 150 parts by weight of powdered caustic soda (whereby the mass absorbs 20 to 60 parts by weight of water from the air) and treating this mixture with 240 to 320 parts by weight of ethyl chloride at a temperature of 110 to 150 (3., for l to 10 hours, washing and drying the obtained product, or by treating 2400 parts by weight of an aqueous alkaline solution of a purified cellulose xanthate containing about 200 parts by weight of the original cellulose and about 200 parts by weight of caustic soda with 500 to 600 parts by weight of (ii-ethyl sulphate at a temperature of about 50 to 55 C., adding to the reacting mixture 325 parts by weight of powdered caustic soda and, after incorporation of the whole or the caustic soda treating the mixture with 1400 parts by weight of diethyl sulphate at a temperature of 70 to 90 0., the di-ethyl sulphate being added infour equal portions, washing the obtained product and drying it.

The finished artificial silk resembles in its properties the artificial silk as obtained in Example I, but is more resistant to very cold water.

Example III The operation is conducted the same as in. Examples I and II, merely with the difference that for preparing the solution designed for spinning, an ethyl ether of cellulose is used, that is insoluble in water at 16 C. and in such below 10 C., but that, particularly in the form of a skin or thread, shows a distinct swelling in very cold water, between 1 and 5 C. Such an ethyl ether of cellulose may be prepared for example, by treating 200 parts by weight of sulphite cellulose with 1800 parts by weight of an 18% solution of caustic soda, pressing the impregnated cellulose down to 500 to 720 parts by weight, incorporating with the residue 250 to 260 parts by weight of powdered caustic soda, adding 450 to 600 parts by weight of ethyl chloride and keeping the reacting mixture at 100 to 150 C., for 6 to 12 hours, washing the obtained product and drying it or by treating 2400 parts by weight of an aqueous alkaline solution of a purified cellulose xanthate containing about 200 parts by weight of the original cellulose and about 200 parts by weight of caustic soda with 500 to 600 parts by weight of di-ethyl sulphate at a temperature of about 50 to 55 0., adding to the reacting mixture 62 parts by weight of powdered caustic soda and 260 parts by weight of di-ethyl sulphate, heating the mass to '70 to 90 C'., repeating these additions and the heating operation, adding then 315 parts by weight of powdered caustic soda, treating the mixture with 780 parts by weight of di-ethyl sulphate at a temperature of 70 to 90 C., the diethyl sulphate being added in three equal portions, washing the obtained product and drying it.

The artificial silk produced by the formula given in this example is like the artificial silk made according to Example II, but is still more resistant to ice cold water.

Example IV The operation is conducted the same as in the foregoing examples, merely with the difference that for making the solution designed for spinning an ethyl ether of cellulose is employed that, being insoluble in water of all temperatures, swells, for example in the form of a film or thread, only in very cold water (1 to 5 C.) to a moderate extent, which swelling is evidenced only by the softness and stretchability of the film or thread in Water at said temperatures. Such a cellulose ether may be prepared, for example by treating 100 parts by Weight of finely divided sulphite cellulose with 50 parts by weight of a 50% caustic soda solution and 200 parts by weight of powdered caustic soda (whereby the mass absorbs 40 to 160 parts by weight of water from the air) and exposing the so obtained product to the action of 360 parts by weight of ethyl chloride at a temperature of 90 to 150 C., for 8 to 10 hours, washing and drying the final product, or by treating 2400 parts by weight of an aqueous alkaline solution of a purified cellulose xanthate containing about 200 parts by weight of the original cellulose and about 200 parts by weight of caustic soda with 500 to 600 parts by weight of di-ethyl sulphate, at a temperature of about 50 to 55 C., adding to the reacting mass 600 parts by weight of powdered caustic soda and 1000 to 1800 parts by weight of di-ethyl sulphate and heating the reacting mass to '70 to 90 0., the caustic and di-ethyl sulphate being added in five equal portions. The final product is Washed and dried. A similar product is obtained by treating 2400 parts by weight of an aqueous alkaline solution of a purified cellulose xanthate containing about 200 parts by weight of the original cellulose and about 200 parts by weight of caustic soda with 500 to 600 parts by weight of di-ethyl sulphate at a temperature of about 50 to 55 C., evaporating the reacting mass to 1080 to 1200 parts by weight, incorporating with the residue 120 to 150 parts by weight of powdered caustic soda, treating the so obtained product withv 165 parts by weight of di-ethyl sulphate at a temperature of 60 to 80 C., repeating this addition and heating operation and washing and drying the obtained product.

The artificial silk made in accordance with this example resembles the artificial silk prepared by the formula given in the foregoing example, but shows a greater resistance to ice cold water.

Example V The mode of operation is the same as in the foregoing examples, merely with the difference that for making the solution intended for spinning a methyl ether of cellulose is employed which, being insoluble in Water at 16 C., swells, for example in the shape of a film or thread, in water below 10 C. Such methyl ether of cellulose may be manufactured for example by treating a soda-cellulose containing 100 parts of cellulose, 200 to 250 parts of caustic soda and 100 to 200 parts of water (prepared either by mixing the aforesaid ingredients or by impregnating cellulose with, say a 20% caustic soda solution, and expelling in vacuo at room temperature, the appropriate amount of water) with 630 to 780 parts by weight of di-methyl sulphate and isolating the final product by washing and drying.

Example VI An ethylor methyl ether of a cellulosic body 7 as employed in the foregoing examples, or a plurality of such ethers and a cellulose acetate (acetyl-cellulose) or cellulose nitrate (nitro-cellulose) are dissolved in a solvent or a mixture of solvents which is capable of dissolving both the alkyl ether of cellulose and the cellulose acetate or cellulose nitrate, for example nitromethane, or methyl alcohol, or methyl acetate, or ethyl acetate, or another ester of an organic acid, or glacial acetic acid, or a mixture of glacial acetic acid and ethylor methyl-alcohol, or a mixture of methylor ethyl acetate with methyl or ethyl alcohol, or a mixture of methylor ethyl alcohol with acetone and methyl or ethyl acetate or the like. The proportion of the alkyl ether of cellulose to the cellulose acetate or nitrate may vary according to the desired properties of the final product from 1 to 9 parts by Weight of the alkyl ether of cellulose to 9 to 1 parts by weight of the cellulose ester. The solution may, in 100-parts contain 3 to 12 parts'by Weight of both the basic ingredients (cellulose ether and cellulose ester) together. The spinning of this solution and finishing of the product is accomplished in a similar manner as in Example I. If a cellulose nitrate be used in admixture with a cellulose ether, the final product may be denitrated in any manner known in the cellulose nitrate art, for example, to convert the nitrate into cellulose hydrate.

The obtained artificial silk shows a fine lustre, suppleness, strength, and resistance to water. In spite of its containing a cellulose acetate or cellulose nitrate it can, owing to its containing an Lil alkyl ether of cellulose that displays the properties underlying the present invention, be dyed with direct (substantive) or acid, or vat, or mordant dyes or sulphur dyes, or basic dyes, etc.

To the solutions used for spinning according to all the foregoing examples, softening agent, or plasticizing agents (such as drying or nondrying oils, fats, fatty acids, phosphoric acid esters of the phenols, high boiling aromatic hydrocarbons, camphor, naphthalene or its derivatives, metal compounds of fatty acids, ethers of phenols, formanilid, acetanilid etc. etc.) may be added.

Example VII 50 parts by weight of an ethyl ether of cellulose insoluble in water at 16 C. but soluble in Water at about C. and below, as employed in Example I, are with stirring or kneading, dissolved in 450 to 500 parts by weight of water at 2 to 5 C. and, if necessary, filtered or strained through cloth. To this solution are then added 500 parts by weight of a cellulose xanthogenate (raw viscose or viscose purified in any known manner) containing 6 to 10% of cellulose. The mixture to which softening agents such as glycerine, sugar, Turkey red oil, soap or the like may be added, is then spun through fine nozzles or openings in known manner into a precipitating bath well known in the viscose art (such as solutions of acids, salts, acid salts, acid and salts, an alcohol, glacial acetic acid etc.) If the precipitating bath is an aqueous liquid, it should have a temperature which the cellulose alkyl ether employed is insoluble in water. In any case 16 C. or above will answer the purpose. To the precipitating bath may also be added organic substances, such as glycerine, sugar, or other water-soluble carbohydrates and the like. The threads leaving the precipitating bath are washed, dried and finished in any manner known in the viscose art.

The solutions or mixtures employed in the foregoing examples for spinning artificial silk may also be used for producing artificial hair in which case the nozzles or openings should have a larger diameter.

The present case is a division of my copending application 322,590, filed November 28, 1928 (now U. S. Patent 1,954,324) which in turn is a division of an earlier case Ser. No. 567,428 filed June 10, 1922.

In many of the mixed liquids employed in dissolving the herein described cellulose ethers, such mixtures contain a liquid which itself is a solvent of these ethers, and a liquid which itself is a non-solvent thereof. Thus a 1:3 mixture of benzol and methyl alcohol (the last mixed solvent liquid referred to in Example I) is such a mixture. Here methyl alcohol itself is a good solvent for these cellulose others, while benzol itself is a non-solvent thereof. Methyl alcohol is considerably more volatile than benzol and likewise is readily miscible with water and with aqueous liquids, whereas benzol is not. What is said here with reference to methyl alcohol is also largely true of ethyl alcohol.

V fhile the benzol is a non-solvent of these ethers, the mixture of this with methyl alcohol (or ethyl alcohol) in the proportions stated in Example 1, (1:3) forms an excellent solvent therefor.

I claim:- I. A process for the production of artificial threads or filaments which consists in spinning into a liquid setting bath, a solution containing an ether derivative of cellulose in solution in a solvent liquid, said setting bath being composed essentially of water and having a temperature of at least 16 C.

2. A process of producing artificial threads or filaments which comprises spinning a solution containing an organic cellulose derivative into a surrounding liquid aqueous bath, such solution having as its composite solvent a mixed liquid composed of at least two organic liquid components which are miscible with each other, at least one of which components has the property, by itself, of dissolving the said cellulose derivatwo, the said last mentioned liquid component being readily miscible with the liquid of said bath whereby the said component may mix with the liquid of said bath, and thereby cause precipita tion of said cellulose derivative in the shaped condition, and said composite solvent also including a liquid component which is a non-solvent of said cellulose derivative and which is not readily miscible with the liquid of said bath.

3. A process of producing artificial structures from a solution of an organic derivative of cellulose, in a composite solvent mixture which consists essentially of an organic liquid which is a solvent of said cellulose derivative and an organic liquid which is a non-solvent of said cellulose derivative, said solvent liquid being one that is readily miscible with water, and said non-sol vent not being readily miscible with water, forming said solution into the shape of the desired artificial material, introducing the shaped solution into a setting bath composed largely at least of water, whereby said setting bath can absorb the solvent for the cellulose derivative, out of the shaped solution, to thereby precipitate the cellu lose derivative in shaped condition, and thereafter drying the said precipitated shaped product.

4. A process of making artificial structures which comprises introducing into an aqueous. liquid bath, a preshaped solution of a cellulose ether which is insoluble in water at and above 16 C., but which is capable of substantially swelling in water at some temperature substantially below 16 C., said solution of cellulose ether being composed essentially of such an ether dissolved in a liquid comprising a substantial proportion of a solvent liquid which is readily miscible with water; whereby the said solventliquid leaves the solution and mixes with said water in said aqueous liquid bath, causing precipitation of the cellulose ether in a shaped condition.

5. A process of producing artificial threads from a cellulose ether which is soluble in a mixture of a lower alcohol and a liquid single ring aromatic hydrocarbon, which comprises dissolving said ether in a solvent mixture composed in large part at least of said alcohol and hydrocarbon, forming the solution into a thread-like stream, and contacting said thread-like stream of solution, with a setting bath composed in large part at least of water, whereby a thread is produced, and drying the thread.

6. A process of producing artificial threads from a cellulose ether which is soluble in a mixture of a lower alcohol and a liquid single ring? aromatic hydrocarbon, which ether is insoluble in water at 16 C., and above, but is capable of becoming swollen in water at some temperature below 16 C., which process comprises dissolving said ether in a solvent mixture composed in large part at least of said alcohol and hydrocarbon, forming the solution into a thread-like stream, and contacting said thread-like stream of solution with a setting bath composed in large part at least of water, whereby a thread is produced, swelling the said thread, acting upon the thread with a dye-bath while in a swollen state, subjecting the thread to a solution of a tanning agent, and drying the thread. 7

A process of making artificial threads which comprises spinning a solution of an organic derivative of cellulose, in an organic liquid menstruum comprising an organic liquid solvent which is water-soluble and another organic liquid which is water-insoluble, into an aqueous liquid, which thereby abstracts the said water- 5 soluble organic liquid solvent from the said solution, to cause precipitation of a thread.

8. A process of making artificial threads which comprises spinning a solution of an organic derivative of cellulose, in an organic liquid menstruum comprising alcohol and benzol, into an aqueous liquid, which takes up the alcohol from said solution, to cause precipitation of a thread.

9. A process of making artificial threads which comprises spinning a solution of an ether of cellulose, in an organic liquid menstruum comprising alcohol and benzol, into an aqueous liquid, which takes up the alcohol from said solution, to cause precipitation of a thread.

10. A process of producing artificial structures from a cellulose ether which is soluble in a mixture of a water-soluble alcohol and a liquid single ring aromatic hydrocarbon which is itself a nonsolvent for said cellulose ether, which comprises dissolving said ether in a mixture composed in large part at least of said alcohol and hydrocar- V bon, forming the solution into the shape of the artificial structure desired, and contacting the so shaped solution with a setting bath composed in large part at least of water, whereby an artificial structure is produced, and drying the said structure.

11. A process for the preparation of threads which contain an alcohol-soluble etherified derivative of cellulose as a substantial component, which comprises spinning a solution containing said cellulose derivative in a solvent mixture which comprises a lower alcohol and an organic liquid which liquid is itself a substantial nonsolvent of said cellulose derivative and which liquid is itself not readily miscible with water, into a setting bath consisting for the most part of water, whereby the said lower alcohol is promptly absorbed by the said water of the setting bath, and whereby the thread is coagulated in said setting bath, and thereafter drying the thread produced.

12. A process of making artificial threads which comprises spinning a solution of an ether of cellulose in an organic liquid menstruum com prising an organic liquid solvent which is watersoluble and another organic liquid which is. water-insoluble, which liquid menstruum is capable of holding said ether of cellulose in solution, into an aqueous liquid, which thereby abstracts the said water-soluble organic liquid solvent from the said solution, to cause precipitation of a thread.

LEON LILIENFELD. 

